The present disclosure relates to an imaging apparatus that has an electronic shutter function, to a method of detecting a flicker in such an imaging apparatus, and to an information processing unit applicable to such an imaging apparatus.
As a type of electronic shutter in an imaging apparatus that includes an imaging device such as a CMOS (Complementary Metal-Oxide Semiconductor), a global shutter type and a rolling shutter type are known. An electronic shutter of the global shutter type performs an electronic shutter operation at the same time in all pixels. Therefore, when using the electronic shutter of the global shutter type, timings of exposure are the same in all pixels. An electronic shutter of the rolling shutter type performs the electronic shutter operation, for example, one horizontal line by one horizontal line. Therefore, when using the electronic shutter of the rolling shutter type, timings of exposure are shifted, for example, one horizontal line by one horizontal line.
In an imaging apparatus as that described above, for example, when a moving image is shot under a light source configured of an alternating-current power source such as a fluorescent lamp, a flicker may be caused by periodical variation in luminance of the light source depending on a relationship between frequency of the alternating-current power source and shutter speed of the electronic shutter in some cases. In particular, when a moving image is shot using the electronic shutter of the rolling shutter type, the timings of exposure are shifted, for example, one horizontal line by one horizontal line. Therefore, a flicker component periodically appears in a particular line, and therefore, lateral stripes are caused. Accordingly, there have been proposed some methods to detect such a flicker component. (See Japanese Unexamined Patent Application Publication No. H08-29864 (JPH08-29864) and No. 2004-7402 (JP2004-7402).)